Added update and delete functionality to article with cascade for variants.

server/migrations/20260126152946_cascade_on_delete.sql

@@ -0,0 +1,7 @@
+-- Add migration script here
+ALTER TABLE public.variant
+DROP CONSTRAINT variant_article_id_fkey,
+ADD CONSTRAINT variant_article_id_fkey
+   foreign key (article_id)
+   references article(id)
+   on delete cascade;